EuroPunch Plier Square 1.5mm EuroPunch Plier Square 1.5mm. These hole punch pliers will punch a 1.5 x 1.5mm square hole in copper or silver as thick as 1mm (18 gauge). With ergonomic handles and tempered replaceable pin, these pliers will save you time and money. The pliers are made of thick carbon steel and come with an extra replaceable pin. Additional replacement pins available in packs of five. Length 135mm (5 inches).